use correct version of acorn in treehugger

test/setup_paths.js

@@ -2,19 +2,25 @@ var modules = require("module");
 var oldResolve = modules._resolveFilename;
 var extraPaths = [
     __dirname + "/../node_modules/ace/lib",
-    __dirname + "/../node_modules/treehugger/lib",
     __dirname + "/../node_modules/v8debug/lib",
     __dirname + "/../"
 ];
-modules._resolveFilename = function(request, paths) {
+var extraPathOverrides = [
+    __dirname + "/../node_modules/treehugger/lib",
+];
+modules._resolveFilename = function(request, parent) {
     // Ensure client extensions can be loaded
     request = request.replace(/^ext\//, "ext.")
             .replace(/^core\//, "cloud9.core/www/core/")
             .replace(/^lib\/chai\//, "chai/");
     // Add the extra paths
     extraPaths.forEach(function(p) {
-        if(paths.paths.indexOf(p) === -1)
-            paths.paths.push(p);
+        if (parent.paths.indexOf(p) === -1)
+            parent.paths.push(p);
     });
-    return oldResolve(request, paths);
+    extraPathOverrides.forEach(function(p) {
+        if (parent.paths.indexOf(p) === -1)
+            parent.paths.unshift(p);
+    });
+    return oldResolve(request, parent);
 };